Truncating mutations of the G-CSF receptor are found during disease course in nearly half of all patients with severe congenital neutropenia. In this issue of the JCI, Liu et al. demonstrate that these mutations confer a competitive clonal advantage upon HSCs in mice and that the advantage is conditional because it is observed only in the presence of the ligand G-CSF (see the related article be...

The enteric nervous system (ENS) is essential for digestive function and gut homeostasis. Here we show that the amorphous neuroglia networks of the mouse ENS are composed of overlapping clonal units founded by postmigratory neural crest-derived progenitors. The spatial configuration of ENS clones depends on proliferation-driven local interactions of ENS progenitors with lineally unrelated neuro...

Although Colombia presents an enormous biological diversity, few studies have been conducted on the population genetics of Trypanosoma cruzi. This study was carried out with 23 Colombian stocks of this protozoa analyzed for 13 isoenzymatic loci. The Hardy-Weinberg equilibrium, the genetic diversity and heterogeneity, the genetic relationships and the possible spatial structure of these 23 Colom...

MOTIVATION DNA sequencing of multiple samples from the same tumor provides data to analyze the process of clonal evolution in the population of cells that give rise to a tumor. RESULTS We formalize the problem of reconstructing the clonal evolution of a tumor using single-nucleotide mutations as the variant allele frequency (VAF) factorization problem. We derive a combinatorial characterizati...

Invasive infections caused by Corynebacterium diphtheriae in vaccinated and non-vaccinated individuals have been reported increasingly. In this study we used multilocus sequence typing (MLST) to study genetic relationships between six invasive strains of this bacterium isolated solely in the urban area of Rio de Janeiro, Brazil, during a 10-year period. Of note, all the strains rendered negativ...

Carboxyfluorescein diacetate succinimidyl ester (CFSE) labelling of naïve lymphocyte populations provides unique insights into the immune response. The clonal nature of immune responses, necessitating clonal expansion to achieve a sufficiently large number of Ag-reactive effector cells, combined with the dependence of lymphocyte differentiation on cell division, underlie the usefulness of CFSE ...

micropropagated plantlets derived from three different grape rootstock genotypes namely, dogridge (vitis champini), so4 (v. berlandieri×v. rupestris) and ari-h-144 (v. vinifera×v. labrusca) were subjected to randomly amplified polymorphic dna (rapd) and inter simple sequence repeats (issr) analyses in order to evaluate their genetic stability and/or detect likely existing variations among in vi...

Despite the increasing popularity of multilocus sequence typing (MLST), the most appropriate method for characterizing bacterial variation and facilitating epidemiological investigations remains a matter of debate. Here, we propose that different typing schemes should be compared on the basis of their power to infer clonal relationships and investigate the utility of sequence data for genealogi...

Clostridium perfringens is a ubiquitous and versatile pathogenic bacterium and is implicated in the etiology of the poultry diseases necrotic enteritis (NE) and poultry gangrene (PG). In this study, multilocus sequence typing was used to investigate genotypic relationships among 139 C. perfringens isolates from 74 flocks. These isolates had multiple disease, host, and environmental origins. The...

Vancomycin resistant Enterococcus faecium (VREF) ia an emerging and challenging nosocomial pathogen. This study aimed to determine the prevalence, risk factors and clonal relationships between different VREF isolates in the intensive care units (ICUs) of the university hospitals in our geographic location. This prospective study was conducted from July, 2012 until September, 2013 on 781 patient...